Trivia: The front and back of the von Trapp house are actually two different houses. Also, the gazebo (which belongs to the house used for the back shots) is across a river from the house. You can take the Sound of Music tour in Salzburg.
Trivia: In the boating scene, Kym Karath (Gretl) nearly drowned when she fell in the water. The scene originally called for Julie Andrews (Maria) to pull her out of the water as Kym couldn't swim, but Andrews fell out of the wrong side of the boat. In fact, the crew had to stop filming to rescue Kym. In the movie Heather Menzies (Louisa) pulls her out - Kym threw up on her after swallowing so much water.
Trivia: "Edelweiss" was the last song Oscar Hammerstein wrote before his death.
Trivia: When filming the sound of music in the scene where Liesl is dancing in the gazebo during the song 'I Am Sixteen Going On Seventeen', where she dances from bench to bench, she actually went through one of the panes of glass on the first jump and sprained her ankle because there were two pairs of shoes she had for that scene (one with rubber grips and one without). The ones with rubber grip were meant for the actual filming not the rehearsal but she had been rehearsing with the ones without rubber grip and someone forgot to change them. She was OK but she had to do the dance with a bandage on her ankle.
Trivia: Kurt sang all of his part except in "So Long, Farewell" where he sings "Goodbye" in a high voice. The actual note was sung by Darleen Carr, the younger sister of Charmian Carr, who was one of the singers used to "fill out" the choral sound of the seven Von Trapp children.
Trivia: In the end when the family is climbing over the hills to safety, it is not really Gretl on the shoulders of Captain Von Trapp. On the DVD, it's revealed that while in Austria, Kym Karath gained a lot of weight. This was one of the last shots filmed and so she was a bit too heavy to be carried on Christopher Plummer's back, so he requested a lighter double.
Trivia: More than one take of the boating scene was filmed (Julie Andrews recalls two). On the one used in the movie, Julie Andrews falls off the far side of the boat. However, in the original theatrical trailer shown on the 40th edition DVD, another take is shown in which everyone falls off the near side.